Method of coloring coal



May 30, 1933.

E. v. COLLINS, JR

METHOD OF COLORING COAL Filed Nov. 28, 1930 M 9:44am Ma ATTORNEYS Patented May 30, 1933 "UNITED STATES PATENT OFFICE manner vr'croa connms, :ra, or :eaooxn'rir, i'mw roux, nssrenoa 'ro DELAWARE; LACKAWANNA & wnsrurm COAL commmz, on NEW Yonx, 1:. Y. a. coarom'rrou or NEW JERSEY marnon or concerns 0on1.

4 Application filed November 28, 1980. Serial No.498,885.

This invention relates to the ap lication of color to coal, and has for its 0 ject the provision of a simple and effective procedure whereby a surface film of color can be applied to coal in an economical manner to give the coal a distinctive characteristic.

In carrying out the invention, I employ suitable chemical reagents which, when combined, will produce a coloring. agent which is adapted -to adhere to the surface of coal. Amon such reagents are mixtures of ferric chlori e and alkali ferricyanides, mixtures of ferric nitrate and alkali ferricyanides, mixtures of potassium permanganate and ferric chloride or nitrate. In using solutions containing ferric chloride or nitrate and alkalfferricyanides, I have found it desirable to employ in addition a small quantity of acid, such'as sulphuric, hydrochloric or nitric acid in the solution. In solutions of potassium permanganate and ferric chloride or nitrate, it is desirable to add sulphuric or nitric acid. The foregoing reagents are cited merely as examples, and other reagents capable of reacting to produce coloring agents on the surface of the coal may be employedin, practicing theinvention.

Ihave discovered that to obtain the most effective results in the application of color to coal, with rea ents such as those mentioned, it is desira le to prepare and; maintainseparate solutions in water of the respective reagents and to combine such solutions approximately at the time of application thereof to the coal. The application of the solutions in this manner avoids premature reaction and loss of some of the coloring agent. It is not essential that the solutions be combined at the instant of application to the coal. The flowing streams of rea ent solutions may be brought together an combined to form a sin 1e stream which is then directed upon t e coal. I prefer, however, to employ a suitable spray nozzle in which the two solutions are com bined and by which a spray of the combined solutions is directed upon the coal which is supported, preferably, upon a traveling conveyor which moves the coal beneath the spray nozzle. The coal may, however, be arranged in stationary layers or piles and the combined solutions may be directed thereon in the form of a spray or otherwise, or the coal may be moved on a traveling conveyor through a bath which is constantly renewed b the introduction of the separate streams o reagents, the bath being preferably of limited volume so that the combined solutions are exhausted substantially. as produced, that is to say, no considerable volume of the combined solutions is permitted to stand for an considerable length of time when coal 1s not being treated therein. Thus I am able to employ the solutions most economically and efiectively, avoiding losses due to remature reaction of the reagents. I fin 1t advantageous, moreover, to connect a source of electrical current respectivel to'the combined solutions and to the coal not important, and I may utilize, therefore,

either direct or alternating current. The amount of current flowin is, in any case, relatively slight. I have and that as little on e sixth of a milliampere is sumvention. The voltage I ewise see'to be of-relatively slightimportanoa'so low as there is suficientpotential to efiect a how of current. I have found, for examp ",';that a potential o'f230 volts is suficientl -kf'l'iower or higher voltage may be used, depending upon the particularjconditions. A convenient arrangement forthe application of cur rent to the coal is a connectlon from one pole of a source of current to a metallic plate or conveyor nonwhich the coal rests,.-;-.the other pole 1w. connected to the "nozzle cient to accomplish the igurpose'ofthe ini upon each of the droplets constituting the spray of combined solutions, and that this charge is dissi ated when the droplets strike the coal, t us causing the reaction to speed up as well as to spread the solution over the surface of the coal more readil and thoroughly. As hereinbefore indicate however, I am b no means certain that the explanation indicated is scientifically correct, and I do not wish, therefore, to be bound by any explanation or theory, since the results described have been obtained and observed in the application of reagents to the'surfa'ce of coal in the manner indicated.

The invention will be more readily under stood by reference to the accompanying drawing, which illustrates diagrammaticab ly a type of apparatus adapted for the application of the procedure, it being understood that other and equivalent means may be utilized.

Referring to the drawing, 5 indicates a suitable conveyor, preferably a metallic belt traveling over suitable pulleys or sprockets 6 in the direction indicated by the arrow. The conveyor may be operated from any suitable source of ower. A hopper 7 is filled with lumps 0 coal 8 which are delivered continuously to the conveyor. As the coal travels on the conveyor it is subjected to a spray of combined solutions of chemicals from a spray nozzle 9'which is supplied through pipes 10 and 11 from sources in which quantities of solutions of the reagents are separately maintained. The coal upon which the spray of combined solutions is directed travels with the conve or and is discharged into a hopper 12 rom which it may be withdrawn. In traveling on the conveyor the coal is more or less coated with produce the coloring agent.

the combined solutions, which by reaction The film of color may be apparent while the coal is still wet with the solutions, and as the coal dries the film becomes more apparent and imparts to. the ,coal a characteristic appearance;

:indicated in' the. drawing, a generator 13m other suitable source of current is provided,

and a conductor 14 is connected to -one pole of'the'generator and to the nozzle 9; The

other pole is connected by a conductor 15 to the journal 1.6 of one of the pulleys or The film is relatively stable, is not easily removed by washing .or abrasion, and 55.

mingled therein, and directed upon the coal.

I find it desirable to add to one or the other of these solutions approximately 2 pounds of nitric acid per hundred gallons of water. In place of ferric chloride crystals in one of the solutions, I prefer to employ 14 pounds of ferric nitrate er hundred allons of water, and to add t ereto 2 poun s of nitric acid per hundred gallons of water. When the solutions asdescribed are combined and spread upon coal, either with or without' the application of electrical current, thereaction results in depositing on the coal an insoluble film of Prussian blue or related chemical compound, which imparts to the coal a distinctive color characteristic. The color is generally bluish, but as the film is relatively thin and tends to be iridescent, it may range from blue to violet and even and yellow.

A similar brownish film may be produced by preparing one per cent so utions of .potasslum permanganate and of ferric chloride or nitrate with the addition of about one per cent of sulphuric acid to either solution. Such solutions may be maintained separately and'combined at approximately the time of application to the coal. The resulting film is an oxide or hydrated oxide of mananese and iron, and when applied to coal 1m arts thereto an iridescent color effect.

he temperatures at which the solutions are maintained and applied to the coal may be varied widely. The reaction tends to be more rapid'as the temperature rises, and it is desirable, therefore, to heat the solutions to a temperature above atmospheric, although satisfactory results can be secured at temperatures above 45 to 50 F. If the solutions are to be heated, steam can be introduced thereto at the spray nozzle or otherwise, or heat can be apphed by steam coils immersed in the receptacles for the respec ive solutions.

The methods described are merely illustrations of different procedures whlch can be used in carrying out the invention, and

the explanations of reactions herein presented are likewise'merely for the purpose of include orange lot the coal with the solutions as combined.

4. The method of coloring coal which comprises tails of the rocedure, the reagents employed therein, and the apparatusutilized without departing from the invention or sacrificing any of the advantages thereof.

I claim: 1. The method of coloring coal which comprises establishing separate flowing streams of solutions of chemical reagents which whencombined will produce a coloring agent, bringing the streams of solutions together approximately at the time of application thereof, directing a spray of the combined solutions upon the coal to be treated, and connecting a source of electrical current. respectively to the coal and to the combined solutions.

2. The method of coloring coal which comprises establishing separate flowing streams of solutions of chemical .reagents which when combined will produce a coloring agent, bringing the streams of solutions together approximately at the time of application thereof, directing the solutions as combined upon the coal to be treated, and connecting a source of electrical current respectively to the coal and to the combined solutions.

3. The method of coloring coal which comprises establishin separate flowing streams of solutions 0% ferric'chloride and an alkali ferricyanide, bringing the streams of solutions together-approximately at the time of application thereof, and treating establishin separate flowing streams of solutions 0 ferric chloride and an alkali ferricyanide, one of the streams containing also an acid, bringing the streams of solutions together approximately at the time of application thereof, and treating the coal with the solutions as combined.

5. The method of coloring coal which comprises establishing separate flowing streams of solutions of ferric nitrate and an alkali ferricyanide, bringing the streams together approximately atthe time of ap-- .plication t ereof, and treating the coal with the solutions as combined.

6. The methods of coloring coal which comprises establishing Y separate flowing streams of'solutions of ferric nitrate and an alkali ferricyanide, one ofthe streams containing also an acid, bringing the streams togetherapproximately at the time of application thereof and treating the coal with the solutions as combined.

7. The method of coloring coal which comprises establishing separate flowing solutions of ferric chloride and an alkali ferricyanide, bringing the streams of solutions together approximately at the timeof applibined solutions.

8. The method of coloring coal which comprises establishing separate flowing solu tions of ferric chloride and an alkali ferricyanide, one of the streams containing also an acid, bringing the streams of solutions together approximately at the time of application thereof and directly a spray of the combined solutions upon the coal to be treated.

'9, The method of coloring coal which comprises establishing separate fiowing solutions of ferric nitrate and an alkali ferricyanide, bringing the streams of' solutions, togetherapproximatel'y at the time of application thereof and directing a spray of the combined solutions upon the coal to be treated.

10. The method of coloring coal which comprises establishing separate flowing solu--.

tions of ferric nitrate and an alkali ferricyanlde, one of the streams containing also an acid, bringing the streams of solutions together approximately at the time of application thereof and directing a spray of combined solutions upon the coal to be treated. v i

11. The method of coloring coal which comprises establishing separate'flowing solutions of ferric chloride and an'alkali ferricyanide, bringin the streams of solutions together approximately at the time of the application thereof, directingtaspmy of the combined solutions upon the coal to betreated, and connecting a so rce of electrical current respectively to t e coal and to the combined solutions.

12. The method of coloring coal which comprises establishing separate flowing solutions of ferric chloride and an alkali ferricyanide, one of the streams containing also an acid, bringing the streams of solutions together approximately at the time of ap plication thereof, directing a spray of the combined solutionsupon the coal to be treated, and connecting a source of electrical current respectively to the coal and to the combined solutions.

13. The method of coloring coal which comprises establishing separate flowing solutions of ferric nitrate and an'alkali ferricyanide, bringing the streams of solutions together approximately at the'time of application thereof, directing a spray of the combined solutions upon the coal to be treated, and connecting a source of electrical current respectively to the coal and to the com-.

bined solutions upon the coal to be treated,

I v and connectin a source of electrical cur-v rent respective y to the coal and to the combined solutions.

15. The method of depositing a colored metal salt upon coal which comprises establishinga flowing stream of a solution of a compound of the metal, the salt of which it is desired to deposit upon the coal, establishing a separate flowing stream of a solu tion of a chemical reagent which will react with the flowing stream of the metal compound to roduce the colored metal salt, bringing tl e streams of solutions together a proximately at the time of application t ereof, and treating thecoal with the solutions ascombined. t 16. The method of depositing acolored 1 metal salt upon coal which comprises establishing a flowing stream of a solution of a 9 compound of the metal, the salt of which it is desired to,deposit upon the coal, estab. lishinn' a separate flowing stream-of a solution of a chemical reagent which will react with the flowing stream of the metal comound to produce the colored metal salt,

gringing the streams of solutions together approximately atthe time of application thereof, and directing thesolutions as combined-upon the coal to be treated. 1 7.-'The method of de ositing a colored metal salt upon coal whic comprises estab-' lishing a flowing stream of a solution of a compound of the metal, the salt of which it is desired to deposit upon the c'oal,-establishing aseparate flowing stream of a solution 'of a chemical reagent which will react with the flowing stream of the metal compound to produce the colored metal salt, .bringing the streams of solutions together 40 a proximately at the time of a plication t ereof, and directing a spray o the combined solutions u onthe coal to betreated. In testimony w ereo'f I aflix my signature.

ERNEST VICTOR COLLINS, JR. 

